Door latch mechanisms of this general type are mounted to the inside face of the door and may include a lock cylinder which is key operated from the outside of the door with a locking lever type actuator on the inside. In some latch designs a latch release blocking member is operatively connected to the lock actuator for movement of the actuator into a blocking position which prevents accidental closing and latching of the door when the latch is locked.
The strike assemblies which are ordinarily used with these types of prior art latches are fastened to the door jamb opposite the latch and employ a vertically extending strike pin which is laterally biased into a latch hook engaging position by means of a pair of coil springs. As the associated door swings closed, an external cam surface on the latch engages the strike pin and pushes it toward the jamb until a latching notch in the latch is opposite the pin, whereupon the pin snaps into the notch. Relatively precise adjustment of the latch and strike are required for proper operation of this type of latch.